NewT=1effective interactions for thef5∕2p3∕2

Abstract

New shell model Hamiltonians are derived for the T = 1 part of the residual interaction in the f 5/2 p 3/2 p 1/2 g 9/2 model space based on the analysis and fit of the available experimental data for 28 57 Ni 29 -28 78 Ni 50 isotopes and 29 77 Cu 50 -50 100 Sn 50 isotones. The fit procedure, properties of the determined effective interaction as well as new results for valence-mirror symmetry and seniority isomers for nuclei near 78 Ni and 100 Sn are discussed.Ni and 91 energy levels for [60][61][62][63][64][65][66][67][68][69][70][71][72] Ni. The nuclei below 60 Ni were not emphasized in the fit due to the increased role PHYSICAL REVIEW C 70, 044314 (2004)

Identification of deformed intruder states in semi-magicNi70

“…5, the experimental levels in 70 Ni are compared to shell-model (SM) calculations including those performed with the antoine [47] and/or NuShellX [48] codes using the jj44bpn [49], jj44pna [50], and JUN45 [51] effective interactions. For all three interactions, the model space is comprised of the neutron p 3/2 , f 5/2 , p 1/2 , and g 9/2 orbitals outside of a 56 Ni core.…”

Medium-spin states in neutron-rich83As and81As

“…Thus the chance that one of these two 3/2 − states or a mixture of both may be the ground state of 83 As cannot be ruled out, a priori. Several sets of residual interactions were proposed to describe some nuclei in this mass region, mainly the N = 50 isotones [35,36]. It is important to note that shell-model (SM) calculations using such sets (see the Fig.…”

“…For instance, when using the set of Ref. [36], the I π = 5/2 − value of 81 31 Ga ground state is well reproduced, while the configuration of the ground state of 83 33 As is predicted to be πp 1 3/2 , thus I π gs = 3/2 − [12]. In summary, the experimental determination of the order of the 5/2 − 1 and 3/2 − 1 states of 83 As is an important issue for the fine tuning of the effective interactions between protons in this mass region.…”

Experimental determination of anIπ=2−ground state inCu72

“…A compelling question in this region is related to the rapid reduction in energy of the 5/2 − state as the νg 9/2 orbital is filled in the Cu isotopes [1,2]. Given that this state remains static at approximately 1 MeV as neutrons fill the fp shell, its abrupt change at N = 40 garnered a great deal of interest and motivated further experimental and theoretical attention [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. A major step in understanding the evolution of nuclear structure in this region was the suggestion to include the monopole term from the tensor force interaction [18,19].…”